MIP Sdk labelling an excel file with UserRights

Hello,

I tried to label in our tenant an excel file adding users and specific rights with class UserRights corresponding to the higly confidental and specific people, in the sample of https://github.com/Azure-Samples/MipSDK-File-Dotnet-ServicePrincipalAuth .

But it doesn't work. All members of the higly confidental can see it.

That should work? Can it be a configuration issue of our tenant, AIP?